In some applications, transistors may be “biased” to operate in a particular fashion. For example, a field effect transistor (FET) may be biased by having a “bias voltage” applied between two device terminals of the FET. Prior art bias circuits may apply a constant gate-to-source voltage (Vgs) between gate and source terminals of a transistor.
Transistor characteristics may vary due to manufacturing variations and/or operating conditions. For example, a transistor's threshold voltage (Vth) may change due to temperature or power supply voltage variations.